GROWTH INHIBITORY EFFECT OF HOUTTUYNIA CORDATA EXTRACT ON STREPTOCOCCUS MUTANS.

Houttuynia cordata is an herbal plant distributed throughout Asia. H. cordata has many bioactive properties, including antibacterial properties. The antibacterial effects of H. cordata on S. mutans remain unknown. Therefore, we treated S. mutans with 1, 3, 5, 10, 20, 30, or 40 mg/mL H. cordata extract at 37°C for 24 h. The antibacterial effect of H. cordata against S. mutans was confirmed using colony forming unit assay and disk diffusion assays. The results of the cell concentration assay demonstrated that H. cordata inhibited the growth of S. mutans in a dose-dependent manner. Prominent growth inhibition was observed after treatment with 10 mg/mL H. cordata extract, and these findings were statistically significant. In addition, no colonies of S. mutans were detected after treatment with 40 mg/mL H. cordata. Disk diffusion assays revealed that 20 mg/mL of H. cordata created a zone of growth inhibition of 11 mm. Therefore, our findings suggest the possibility of using H. cordata in the treatment and prevention of dental caries.

Exploring the role of flavonoids in caries-affected dentin adhesion: A comprehensive scoping review.

OBJECTIVES: The aim of this scoping review was to evaluate the available scientific evidence regarding the use of flavonoids in the treatment of caries-affected dentin focusing on bonding to dentin. METHODS: A comprehensive literature search was performed in five databases from March 2022 and updated in April 2023: PubMed, EMBASE, Scopus, Web of Science, and Scielo. Additionally, the references of included studies were manually searched. Gray literature was excluded from the review. STUDY SELECTION: Inclusion criteria included in vitro, in situ, and in vivo studies (animal or human) published in English. Abstracts, reviews, case reports, book chapters, doctoral dissertations, guidelines, and studies using pure plant extracts were excluded. Data collected from the selected studies were summarized and subjected to narrative and descriptive analysis. Out of the 91 studies identified, only 16 studies met the inclusion criteria. RESULTS: The review analyzed eight different flavonoids (hesperidin, galardin, proanthocyanidin, genipin, quercetin, naringin, epigallocatechin-3-gallate, and other catechins subtypes) used as pretreatment or loaded into adhesive systems, primers, and phosphoric acid. The use of flavonoids improved the mechanical properties of the materials and modified the biological properties of the dentin, reducing collagen loss by the inhibition of proteolytic activity of matrix metalloproteinases (MMPs). CONCLUSIONS: Based on the findings of this scoping review, it can be concluded that the use of flavonoids as pretreatment or incorporation into dental materials preserves collagen in the hybrid layer, inhibiting the MMPs activities, modifying the collagen fibrils of the dentin matrix and improving the mechanical properties of the dental adhesive systems. Therefore, it represents a promising approach for promoting dentin biomodification. This can result in more stable bonding of adhesive restorations to caries-affected dentin.

Evaluation of Stain Removal Efficacy and Color Stability of Three Different Dentifrices on Artificially Stained Enamel Surface-An In Vitro Study.

AIM: The aim of the present study was to assess the stain removal ability and color stability of three distinct dentifrices on artificially stained enamel surface. MATERIALS AND METHODS: This study included 75 intact, healthy premolars free of dental caries that were extracted during orthodontic therapy. The samples were allowed to dry for 6 hours after being submerged in the prepared tea solution for roughly 18 hours every day. Then this procedure was repeated for seven successive days. All samples were randomly divided into three experimental groups with 25 samples in each group. Group I: control dentifrice, group II: dentifrice containing hydrogen peroxide, group III: dentifrice containing papain and bromelain. A specially designed toothbrushing simulator was used to brush every sample in the relevant group. Using a spectrophotometer and a measurement program, color measurement was evaluated after staining process after 4 weeks and 8 weeks of teeth cleaning. Using a profilometer, the surface roughness values (Ra) were assessed. RESULTS: After 8 weeks of brushing of stained samples, the color stability was better in dentifrice containing hydrogen peroxide (1.14 ± 0.11) followed by dentifrice containing papain and bromelain (1.22 ± 0.08) and control group (1.30 ± 0.09). And after 8 weeks of brushing of stained samples, the surface roughness was more in dentifrice containing hydrogen peroxide (0.237 ± 0.02) followed by dentifrice containing papain and bromelain (0.229 ± 0.13) and control group (0.207 ± 0.05). CONCLUSION: The present study concluded that the dentifrice containing hydrogen peroxide showed a superior whitening effect on the stained enamel surface than dentifrice containing papain and bromelain and control dentifrice. CLINICAL SIGNIFICANCE: The development of various dentifrice products has been greatly aided by the increased demand for an improved esthetic appearance. Teeth's natural color and any external stains that could accumulate on the tooth surface combine to determine a tooth's color. Additionally, the use of whitening dental pastes to remove external stains has grown in favor. With the development of these whitening toothpastes, dentifrices' ability to lessen or eliminate extrinsic dental stains has increased. How to cite this article: Mishra D, Kamath DG, Alagla M, et al. Evaluation of Stain Removal Efficacy and Color Stability of Three Different Dentifrices on Artificially Stained Enamel Surface-An In Vitro Study. J Contemp Dent Pract 2024;25(1):68-71.

Treatment of dental biofilm-forming bacterium Streptococcus mutans using tannic acid-mediated gold nanoparticles.

Biosynthesized gold nanoparticles (AuNPs) are highly attracted as a biocompatible nanodrug to treat various diseased conditions in humans. In this study, phytochemical tannic acid-mediated AuNPs (TA-AuNPs) are successfully synthesized and tested for antibacterial and antibiofilm activity against dental biofilm-forming Streptococcus mutans biofilm. The synthesized TA-AuNPs are appeared as spherical in shape with an average size of 19 nm. The antibacterial potential of TA-AuNPs was evaluated using ZOI and MIC measurements; while, antibiofilm efficacy was measured by checking the eradication of preformed biofilm on the tooth model. The ZOI and MIC values for TA-AuNPs are 25 mm in diameter and 4 µg/mL, respectively. The MTT assay, CLSM, and SEM results demonstrate that the preformed S. mutans biofilm is completely eradicated at 4xMIC (16 µg/mL) of TA-AuNPs. Finally, the present study reveals that the synthesized TA-AuNPs might be a great therapeutic drug to treat dental biofilm-forming bacterium S. mutans.

Medicinal herbs, especially Hibiscus sabdariffa, inhibit oral pathogenic bacteria.

OBJECTIVES: Medicinal herbs are plants with potential medicinal and health benefits. In recent years, they are being increasingly used as a treatment alternative owing to their effectiveness against various diseases. In this study, we investigated the inhibitory effects of 15 medicinal herbs on causative bacteria for dental caries and periodontal disease. METHODS: This study evaluated the effects of the extracts of 15 medicinal herbs on growth and biofilm formation in five oral pathogenic bacterial strains. The herbs were processed into extracts, and bacterial strains were cultured. Then, bacterial growth and biofilm formation were assessed using various methods. Finally, the extract of the herb Hibiscus sabdariffa (hibiscus) was analyzed using high-performance liquid chromatography. RESULTS: Incubation of bacteria with the herbal extracts showed that hibiscus exerted a significant inhibitory effect on all the oral pathogenic bacterial strains evaluated in this study. In addition, the pigment delphinidin-3-sambubioside, which is found in hibiscus extract, was identified as a particularly important inhibitory component. CONCLUSIONS: These results lay the ground work for the potential development of novel therapeutic or preventive agents against dental caries and periodontal disease, two major oral diseases.

Association of Papacarie Duo® and low-level laser in antimicrobial photodynamic therapy (aPDT).

Dental caries is a multifactorial, non-communicable disease. Effective treatment options for minimally invasive removal of carious tissue include Papacarie Duo® gel and antimicrobial photodynamic therapy (aPDT). aPDT involves a combination of a light source and photosensitizer. Given that Papacarie Duo® contains a percentage of blue dye, this study aims to explore the antimicrobial potential of Papacarie Duo® when associated with a light source against Streptococcus mutans strains. The chosen light source was a low-power diode laser (λ = 660 nm, E = 3 J, P = 100 mW, t = 30 s). To assess antimicrobial capacity, planktonic suspensions of Streptococcus mutans were plated on Brain Heart Infusion Agar (BHI) to observe the formation of inhibition halos. The studied groups included methylene blue (0.005%), Papacarie Duo®, distilled water (negative control), 2% chlorhexidine (positive control), Papacarie Duo® + laser, and methylene blue (0.005%) + laser. Following distribution onto plates, each group was incubated at 37 °C for 48 h under microaerophilic conditions. Inhibition halos were subsequently measured using a digital caliper. The results showed that chlorhexidine had the greatest antimicrobial effect followed by the group of irradiated methylene blue and irradiated Papacarie Duo®. All experimental groups demonstrated antimicrobial potential, excluding the negative control group. The study concludes that Papacarie Duo® exhibits antimicrobial properties when associated with a low-power diode laser.

Inhibition of pathogenic microbes in oral infectious diseases by natural products: Sources, mechanisms, and challenges.

The maintenance of oral health is of utmost importance for an individual's holistic well-being and standard of living. Within the oral cavity, symbiotic microorganisms actively safeguard themselves against potential foreign diseases by upholding a multifaceted equilibrium. Nevertheless, the occurrence of an imbalance can give rise to a range of oral infectious ailments, such as dental caries, periodontitis, and oral candidiasis. Presently, clinical interventions encompass the physical elimination of pathogens and the administration of antibiotics to regulate bacterial and fungal infections. Given the limitations of various antimicrobial drugs frequently employed in dental practice, the rising incidence of oral inflammation, and the escalating bacterial resistance to antibiotics, it is imperative to explore alternative remedies that are dependable, efficacious, and affordable for the prevention and management of oral infectious ailments. There is an increasing interest in the creation of novel antimicrobial agents derived from natural sources, which possess attributes such as safety, cost-effectiveness, and minimal adverse effects. This review provides a comprehensive overview of the impact of natural products on the development and progression of oral infectious diseases. Specifically, these products exert their influences by mitigating dental biofilm formation, impeding the proliferation of oral pathogens, and hindering bacterial adhesion to tooth surfaces. The review also encompasses an examination of the various classes of natural products, their antimicrobial mechanisms, and their potential therapeutic applications and limitations in the context of oral infections. The insights garnered from this review can support the promising application of natural products as viable therapeutic options for managing oral infectious diseases.

The in-vitro development of novel enzyme-based chemo-mechanical caries removal agents.

OBJECTIVES: Bromelain is a potent proteolytic enzyme that has a unique functionality makes it valuable for various therapeutic purposes. This study aimed to develop three novel formulations based on bromelain to be used as chemomechanical caries removal agents. METHODS: The novel agents were prepared using different concentrations of bromelain (10-40 wt. %), with and without 0.1-0.3 wt. % chloramine T or 0.5-1.5 wt. % chlorhexidine (CHX). Based on the enzymatic activity test, three formulations were selected; 30 % bromelain (F1), 30 % bromelain-0.1 % chloramine (F2) and 30 % bromelain-1.5 % CHX (F3). The assessments included molecular docking, Fourier-transform infrared spectroscopy (FTIR), viscosity and pH measurements. The efficiency of caries removal was assessed by DIAGNOdent pen, measuring the excavation time and number of applications, followed by a morphological evaluation of the remaining dentine using scanning electron microscopy (SEM). The results were compared to Brix 3000 as a control. RESULTS: The chloramine and chlorhexidine were chemically compatible with bromelain without compromising the enzyme activity. All experimental formulations showed higher viscosity and pH in comparison to Brix 3000. The DIAGNOdent readings were <20 in all groups, and the lowest readings were observed in F2. The excavation time and number of applications were lowest in F2 and F1. Both F2 and F3 produced smooth dentine surfaces with less tissue debris, but more patent dentine tubules were observed in F1 and F2. CONCLUSIONS: The bromelain-contained formulations showed a potential to be used as chemomechanical caries removal agents in vitro. Further laboratory and clinical studies are needed to validate this claim. CLINICAL SIGNIFICANCE: The bromelain from pineapple stem has broad specificity for cleavage the peptide bonds in denatured protein to facilitate their removal. The study proved the efficiency of this enzyme to remove the dental caries chemomechanically when used alone or conjugated with chloramine and/or chlorhexidine to enhance the disinfecting and cleansing properties.

EVALUATION OF THE ANTI-CARIES EFFECT OF LESPEDEZA CUNEATA EXTRACT AGAINST STREPTOCOCCUS MUTANS.

The purpose of this study was to identify the antimicrobial activity of Lespedeza cuneata extract, a natural medicine, against a main causative bacterium of dental caries, Streptococcus mutans (S. mutans). Lespedeza cuneata purchased from Hwalim Natural Drug Co., Ltd. (Busan, South Korea) was immersed in 70% ethanol for 12 h, and concentrated Lespedeza cuneata extract was applied to S. mutans diluted to 6×105 CFU/mL at the concentrations of 0, 1.25, 2.5, 5, 10, 20, and 40 mg/ml. Then the colony-forming units (CFUs) were checked at 6 and 24 h to evaluate the antimicrobial activity of the extract. The CFUs and survival rate of S. mutans according to the concentration showed a higher mortality rate as the concentration of Lespedeza cuneata extract increased. In the time-dependent changes, the minimal inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were 1.25 and 40 mg/mL or more, respectively, at 6 h, but they were 1.25 and 5 mg/mL, respectively, at 24 h. Therefore, Lespedeza cuneata extract is considered an excellent natural antibiotic for the prevention and treatment of dental caries, a typical oral disease, because it has excellent dental caries development suppression and bacteria extermination effects.

Remineralization Potential of a Novel Biomimetic Material (Self-assembling Peptide P11-4) on Early Enamel Caries: An In Vitro Study.

AIM: To assess the remineralizing potential of self-assembling peptide P11-4 and compare it to the remineralizing potential of fluoride varnish using DIAGNOdentTM, as well as the amount of mineral gain after application of fluoride varnish and self-assembling peptide P11-4. MATERIALS AND METHODS: This study included 20 premolars extracted during orthodontic therapy with all surfaces intact and free of hypoplastic regions, white spot lesions (WSL) and dental caries. The teeth sample for Curodont RepairTM (self-assembling P11-4) and Bifluorid 10® (fluoride varnish) was equally divided. On each tooth surface, a 2 × 2 mm window was created. The samples were immersed in a demineralizing solution for 96 hours before being subjected to DIAGNOdentTM pen reading, ICDAS-II scoring, and scanning electron microscopy-energy-dispersive X-ray (SEM-EDX) analysis on one half of the sample. The remineralizing agents were applied to the second half of the sample according to the manufacturer's instructions and placed in artificial saliva for 21 days, with the artificial salvia being replaced every 24 hours. After 21 days, the second half of the sample was subjected to DIAGNOdentTM pen reading, ICDAS-II score, and SEM-EDX analysis. RESULTS: Following remineralization, the DIAGNOdentTM pen and ICDAS-II score values differed statistically between the two groups, with the Bifluorid 10® group reporting higher mean values (p > 0.05) using t-test analysis. Energy-dispersive X-ray analysis using the t-test revealed a statistically significant result for remineralization (p < 0.05), with CurodontTM Repair group (55.150.84) reporting better mean values than Bifluorid 10® for phosphorus and calcium, but Bifluorid 10® reporting a higher result in remineralization (p < 0.05) than CurodontTM Repair for fluoride. CONCLUSION: CurodontTM Repair showed better remineralizing potential compared with Bifluorid 10® varnish. In terms of the mineral gain, CurodontTM Repair showed better results for calcium and phosphorus post-remineralization. Whereas Bifluorid 10® showed a higher gain in terms of fluoride. Self-assembling peptide P11-4 can be used as an alternative to fluoride varnish for remineralizing WSL. CLINICAL SIGNIFICANCE: Self-assembling polypeptide P11-4 is a novel remineralizing agent for initial enamel lesions, which is the least-invasive method of enamel remineralization.

Effect of fluoride gels with nano-sized sodium trimetaphosphate on the in vitro remineralization of caries lesions.

OBJECTIVE: To evaluate the effects of fluoride (F) gels supplemented with micrometric or nano-sized sodium trimetaphosphate (TMPmicro and TMPnano, respectively) on the in vitro remineralization of caries-like lesions. METHODOLOGY: Bovine enamel subsurface lesions (n=168) were selected according to their surface hardness (SH) and randomly divided into seven groups (n=24/group): Placebo (without F/TMP), 4,500 ppm F (4500F), 4500F + 2.5% TMPnano (2.5% Nano), 4500F + 5% TMPnano (5% Nano), 4500F + 5% TMPmicro (5% Micro), 9,000 ppm F (9000F), and 12,300 ppm F (Acid gel). The gels were applied in a thin layer for one minute. Half of the blocks were subjected to pH cycling for six days, whereas the remaining specimens were used for loosely- (calcium fluoride; CaF2) and firmly-bound (fluorapatite; FA) fluoride analysis. The percentage of surface hardness recovery (%SHR), area of subsurface lesion (ΔKHN), CaF2, FA, calcium (Ca), and phosphorus (P) on/in enamel were determined. Data (log10-transformed) were subjected to ANOVA and the Student-Newman-Keuls' test (p<0.05). RESULTS: We observed a dose-response relation between F concentrations in the gels without TMP for %SHR and ΔKHN. The 2.5% Nano and 5% Micro reached similar %SHR when compared with 9000F and Acid gels. For ΔKHN, Placebo and 5% Nano gels had the highest values, and 5% Micro, 2.5% Nano, 9000F, and Acid gels, the lowest. All groups had similar retained CaF2 values, except for Placebo and Acid gel. We verified observed an increase in Ca concentrations in nano-sized TMP groups. Regarding P, TMP groups showed similar formation and retention to 9000F and Acid. CONCLUSION: Adding 2.5% nano-sized or 5% micrometric TMP to low-fluoride gels lead to enhanced in vitro remineralization of artificial caries lesions.

Evaluation of photodynamic therapy on nanoparticles and films loaded-nanoparticles based on chitosan/alginate for curcumin delivery in oral biofilms.

Nanoparticles and nanoparticle-loaded films based on chitosan/sodium alginate with curcumin (CUR) are promising strategies to improve the efficacy of antimicrobial photodynamic therapy (aPDT) for the treatment of oral biofilms. This work aimed to develop and evaluate the nanoparticles based on chitosan and sodium alginate encapsulated with CUR dispersed in polymeric films associated with aPDT in oral biofilms. The NPs were obtained by polyelectrolytic complexation, and the films were prepared by solvent evaporation. The photodynamic effect was evaluated by counting Colony Forming Units (CFU/mL). Both systems showed adequate characterization parameters for CUR release. Nanoparticles controlled the release of CUR for a longer period than the nanoparticle-loaded films in simulated saliva media. Control and CUR-loaded nanoparticles showed a significant reduction of 3 log10 CFU/mL against S. mutans biofilms, compared to treatment without light. However, biofilms of S. mutans showed no photoinactivation effect using films loaded with nanoparticles even in the presence of light. These results demonstrate the potential of chitosan/sodium alginate nanoparticles associated with aPDT as carriers for the oral delivery of CUR, offering new possibilities to improve the treatment of dental caries and infections. This work will contribute to advances in the search for innovative delivery systems in dentistry.

The effect of different concentrations of fluoride in toothpastes with or without bioactive glass on artificial root caries.

OBJECTIVE: To investigate the effect of different toothpastes either containing 5,000ppm-F, 1,450ppm-F or bioactive glass (BG) with 540ppm-F on artificial root carious lesions (ARCLs). METHOD: The crowns of 23 extracted sound teeth were removed leaving their roots only. Subsequently, each root was divided into four parts. A total of 15 sound root dentine (SRD) was left untreated as baseline. The ARCLs were developed for the remaining roots using demineralisation solution (pH-4.8). 15-ARCLs samples were then left untreated. The rest of samples were divided into four groups (n = 15 each) and treated with Group-1(BG with 540ppm-F); Group-2(5000ppm-F); Group-3(1450ppm-F) and Group-4(deionised water). 13-day pH-cycling included using demineralisation solution for 6 h, then placing samples into remineralisation solution (pH-7) for 16 h. Each sample was brushed with the assigned toothpaste twice a day during pH-cycling. Fluoride concentrations at each time point were measured using F-ISE, whilst calcium (Ca2+) and phosphorus (P) ion release was determined using ICP-OES, KHN, XRD, 19F-MAS-NMR analyses. RESULTS: KHN showed significant surface changes for each group (p<0.001). The uptake of Ca2+ occurred at days 1-2, phosphorus ion loss was high when compared to the uptake in all groups. XRD showed presence of sharp diffraction lines evidencing apatite formation for Groups 1-3. 19F-MAS-NMR confirmed fluorapatite presence in Groups 1-3. CONCLUSION: All toothpastes were promising in fluorapatite formation. BG with 540ppm-F toothpaste released more ions (Ca2+and P) and reharden the artificial root carious lesions when compared to other groups. However, 1450ppm-F toothpaste showed more fluoride-substituted apatite formation whilst 5000ppm-F toothpaste had more fluorapatite formation. CLINICAL SIGNIFICANCE: Toothpaste containing BG with 540ppm-F, 5000ppm-F and 1450ppm-F toothpastes are likely to have a significant impact in reversing and arresting root caries. However, randomised controlled double-blinded clinical trials are required to translate these results into clinical practice.

Applications of photothermally mediated nanohybrids for white spot lesions in orthodontics.

In orthodontic treatment, cariogenic bacteria in the oral cavity are the main cause of enamel white spot lesions (WSLs). Therefore, to effectively prevent and treat WSLs, it is crucial to inhibit the cariogenic bacterial activity while promoting the remineralization of demineralized tooth enamel. However, fluoride preparations commonly used for the prevention and treatment of WSLs can induce dental fluorosis if ingested in excess, and their remineralization effect is limited by the residual hydroxyapatite (HAp) content and salivary Ca2+ and PO43- levels. In this study, we propose a strategy (CMCS/ACP@PDA) for antibacterial and remineralization of WSLs by a nanohybrid of carboxymethyl chitosan (CMCS)-stabilized amorphous calcium phosphate (ACP) loaded polydopamine nanoparticles (PDA NPs) based on biomimetic remineralization techniques and biocompatible near-infrared (NIR) photoactivation therapy. The nanohybrid utilizes the excellent photothermal conversion ability of polydopamine for antimicrobial purposes, while CMCS with its own positive and negative charges (-NH3+ and -COO-) acts as a biomimetic mineralizing agent to stabilize ACP, supplemented with abundant Ca2+ and PO43- for remineralization of demineralized enamel. The results showed that CMCS/ACP@PDA could effectively inhibit the adhesion of cariogenic Streptococcus mutants (S. mutants) with high bactericidal rates. In addition, the remineralization of demineralized enamel by nanohybrid was more effective after 7 days of in vitro mineralization. This study provides a theoretical and experimental basis for the use of CMCS/ACP@PDA nanohybrid materials as potential materials against WSLs.

Exploring the Potential of a Herbal Nanoemulsion as an Antimicrobial Mouthwash.

The study aimed to formulate a nanoemulsion, combine it with aqueous extracts of herbal powders, and test its efficiency as caries-preventing mouthwash. Formulation of nanoemulsion using microfluidizer, characterization of nanoemulsion, minimum inhibitory concentration, adherence test, biofilm assay, and artificial mouth assay was carried out. The biofilms of Streptococcus mutans, Lactobacillus casei, Actinomyces viscosus, and a combination of the three cultures were developed and treated with formulations to study the inhibitory effect of the samples. In artificial mouth assay, human tooth samples were used as surfaces to grow the biofilm of S. mutans, and daily, the teeth were treated with the formulations to test their real-time efficiency. The nanoemulsion was characterized using dynamic light scattering and the size of the particles was within the 100-300 nm range. Above 50 °C, the nanoemulsion combined with plant extract lost its emulsified state within 2 h of incubation, while the nanoemulsion was stable. Nanoemulsion with plant extract inhibited the adherence of L. casei (73%) and biofilm of L. casei (66%). In artificial mouth assay, after 10 days of nanoemulsion, nanoemulsion with plant extract showed DIAGNOdent pen values 3.5 and 2 respectively whereas the negative control value was 14.4 indicating caries initiation. The nanoemulsion with plant extract showed anti-adherence and anti-biofilm activity and hence can be used as a potent anticariogenic mouthwash.

Nanomaterials-mediated photodynamic therapy and its applications in treating oral diseases.

Oral diseases, such as dental caries, periodontitis and oral cancer, have a very high morbidity over the world. Basically, many oral diseases are commonly related to bacterial infections or cell malignant proliferation, and usually located on the superficial positions. These features allow the convenient and efficient application of photodynamic therapy (PDT) for oral diseases, since PDT is ideally suitable for the diseases on superficial sites and has been widely used for antimicrobial and anticancer therapy. Photosensitizers (PSs) are an essential element in PDT, which induce the generation of a large number of reactive oxygen species (ROS) upon absorption of specific lights. Almost all the PSs are small molecules and commonly suffered from various problems in the PDT environment, such as low solubility and poor stability. Recently, reports on the nanomedicine-based PDT have been well documented. Various functionalized nanomaterials can serve either as the PSs carriers or the direct PSs, thus enhancing the PDT efficacy. Herein, we aim to provide a comprehensive understanding of the features of different oral diseases and discuss the potential applications of nanomedicine-based PDT in the treatment of some common oral diseases. Also, the concerns and possible solutions for nanomaterials-mediated PDT are discussed.

Antimicrobial Activity of Crataegi fructus Extract Used for Potential Application in the Prevention and Treatment of Oral Diseases.

Background and Objectives: This study evaluated the antimicrobial effect and cytotoxic potential of the natural Crataegi fructus extract against Streptococcus mutans (S. mutans), the causative agent of dental caries, which is a typical oral disease, and Candida albicans (C. albicans), which causes oral candidiasis. Materials and Methods: Crataegi fructus was shaken in 70% ethanol for 12 h to obtain samples through enrichment and lyophilization. Then, 1, 5, 10, 20, 30, and 40 mg/mL of the Crataegi fructus extract were applied to S. mutans and C. albicans to demonstrate its antimicrobial effect after 24 h. The stability of Crataegi fructus extract on the survival rate of human keratinocytes (HaCaT) was confirmed using water-soluble tetrazolium salt (WST-1) analysis. A one-way ANOVA determined the difference between each group. A Tukey HSD test was performed as a post-hoc analysis at the 0.05 significance level. Results: Crataegi fructus extract showed antimicrobial effects against S. mutans and C. albicans that increased in a concentration-dependent manner. However, high concentrations affected cell growth and lowered cell survival. The half maximal inhibitory concentration (IC50 value) of Crataegi fructus extract showed a survival rate of 53.04% at a concentration of 30 mg/mL, which was found to be applicable. Conclusions: Thus, Crataegi fructus extract may be used as a natural material for the prevention and treatment of oral diseases. Crataegi fructus demonstrates optimal antimicrobial effects without affecting cell proliferation and growth at 30 mg/mL concentration.

Antimicrobial photodynamic therapy as an adjunctive treatment to ultrasound for the dentin caries-like lesion removal.

OBJECTIVE: To evaluate in vitro the efficacy of ultrasound device to remove caries-like dentin and the curcumin-mediated antimicrobial photodynamic therapy (aPDT) to decontaminate the affected dentin. METHODS: Bovine dentin specimens (n = 173) of 4 × 4 × 2 mm were first submitted to Knoop surface microhardness to standardize the specimens (29 ± 3 KHN). Artificial caries lesion was induced by Streptococcus mutans strain by biological model for 7 days. Infected dentin was removed (1 min) with the following techniques: dentin excavator, bur at low-speed rotation and ultrasound device. After that, aPDT application was performed using blue LED under 460 nm. Polarized light microscopy (PLM), removal rate (n = 10), cross-sectional microhardness (n = 10), colony forming units per milliliter (CFU) (n = 9) and confocal laser microscopy (CM) (n = 2) were performed. ANOVA with Welch correction, post-hoc Games-Howell and two-way ANOVA followed by Tukey's post-hoc tests were used. RESULTS: PLM confirmed the caries lesion formation with a depth of ∼147.9 µm. Groups treated with ultrasound showed lower removal rate (p = 0.001). Regardless of the treatment, the microhardness values increased as function of depth (p ≤ 0.05). Carbide bur showed the highest microhardness value, followed by ultrasound and excavator. CFU and CM showed a significant reduction in S. mutans after aPDT application. CONCLUSION: Ultrasound was efficient, since it removed infected dentin, preserving the affected dentin and aPDT can be used as a complementary therapy to decontaminate the affected dentin. CLINICAL SIGNIFICANCE: Ultrasound device may help the clinician to remove dentin caries-like lesions since it is a conservative technique and provided the removal of infected dentin, preserving the affected dentin. aPDT application may be used as a complimentary technique to promote antibacterial effect and possibly minimize the risk of secondary caries.

3D printing of a controlled fluoride delivery device for the prevention and treatment of tooth decay.

Dental decay is a highly prevalent chronic disease affecting people from all ages. Clinically, fluoride supplementation is the primary strategy in the prevention of dental decay. However, the current existing self-application formulations such as gels or mouthwashes are rapidly cleared after administration, resulting in modest efficacy even after repeated applications. Therefore, a user-friendly formulation that can provide sustained fluoride release in the oral cavity is of great interest for dental decay prevention. Herein, we report the utilization of fused deposition modelling to fabricate personalised mouthguards, which allow local and prolonged fluoride elution. Composite filaments comprising sodium fluoride and polymers with tuneable hydrophobicity were produced using blends of poly(ε-caprolactone) (PCL) and poly(vinyl alcohol) or poly(ethylene glycol) (PEG). The materials exhibited suitable mechanical properties for dental devices as well as different release kinetics depending on their composition. Ex vivo studies were performed on decayed human teeth using the 3D printed tooth caps that precisely fit the complex geometries of each specimen. A significant elevation of fluoride content in the lesion mineral in contact with the PCL/PEG tooth caps was achieved compared to the ones in contact with solutions mimicking dental care products. In conclusion, this study suggested that a sustained localized drug release of fluoride from personalised 3D printed mouthguards at the device-enamel interface can improve the incorporation of fluoride in the tooth matrix and prevent lesion progression.

The antimicrobial and antibiofilm effects of three herbal extracts on Streptococcus mutans compared with Chlorhexidine 0.2% (in vitro study).

There is a special focus on using natural materials and herbal plants to prevent dental caries. Previous studies showed that some herbal plants have antimicrobial effects on oral pathogens. Thus we investigated the antimicrobial effects of three herbal extracts (Carum copticum, Phlomis bruguieri, and Marrubium parviflorum) on the growth of Streptococcus mutans, as the most important bacteria causing dental caries. First, plant methanolic extracts were prepared. Then, to evaluate the antimicrobial activity of the three herbal extracts, the agar well diffusion method and MIC were performed. The biofilm formation was carried out using a broth dilution method with 2% glucose-supplemented BHIS in sterile 96-well microplates. Serial dilutions (50, 25, 12.5, 6.25, 3.12 mg/ml) of extracts were prepared. Next, a 0.5 McFarland Suspension of S. mutans was added to wells. The inhibitory effect on biofilm formation was measured by the ELISA reader apparatus. The assay was repeated three times, and the average was calculated as 3. The results were compared with those of Chlorhexidine 0.2%. Carum copticum showed a better effect in the agar well diffusion method than others. MIC of the extracts of Carum coptimum, Phlomis bruguieri, and Marrubium parviflorum were 3.12, 6.25, and 12.5 mg/ml, respectively. Overall, the highest activity belonged to Carum copticum extract. For the anti-biofilm effect, the OD values of Carum copticum and Marrubium parviflorum were significantly different from that of Phlomis bruguieri. Although all of the methanolic herbal extracts can inhibit S. mutans growth and remove the biofilm, the effect of Carum copticum was better than Phlomis bruguieri and Marrubium parviflorum. Further studies are recommended to indicate how these extracts perform against the bacteria.